The invention is directed to graphite fiber reinforced metal matrix composite structures. Graphite fiber reinforced magnesium matrix composite structures (hereinafter referred to as "Gr/Mg MMC") are a recent development in lightweight and high stiffness structural materials. These materials are attractive because they combine low density, high stiffness moduli, and low coefficients of thermal expansion in a single material. Gr/Mg MMC materials are presently manufactured in useful shapes, such as sheets and tubes, by making a lay-up of the desired shape from a precursor Gr/Mg MMC form, such as, thin tape or wire. The lay-up is then bonded together and densified by a hot press diffusion bonding process. Hot press diffusion bonding processes presently used include heated die pressing, inflatable mandrel/pressure bag compressing, pultrusion, and hot isostatic pressing. To be successful, these processes must produce pressures on the order of 3,000 psig to 5,000 psig at temperatures around 900.degree. F. to achieve proper consolidation of the composite precursor materials. To obtain and contain this combination of high pressure and elevated temperature to consolidate the Gr/Mg MMC precursor materials, heavy, complex and expensive tooling is required. This tooling becomes even larger, more complex and even much more expensive as the desired size of the Gr/Mg MMC structure increases in size. The tooling requirements for hot press diffusion bonding pose significant limits on the maximum size of the structure that can be produced.
If less costly means could be developed for producing the Gr/Mg MMC structures, such structures would be more widely utilized, such as for large spacecraft structures, space based telescopes, spaced based optical systems, spacecraft and space stations. Such structures will also have application in missiles and in aircraft, both military and civilian.